This invention relates to an ultrasonic surgical tool or instrument. This invention also relates to a method for manufacturing the tool or instrument.
U.S. Pat. No. 6,379,371 discloses an ultrasonic surgical blade, particularly for cutting bone tissue, which has a blade body with a smooth continuous cutting edge and a shank connected at one end to the blade body and operatively connectable at an opposite end to a source of ultrasonic vibrations. The shank is provided with an axially extending bore for the conveyance of cooling fluid to the cutting edge, while the blade body is provided with an axially extending through-slot communicating at one end with the bore. The blade body is preferably provided at an end opposite the shank with a recess communicating, with the bore for distributing fluid from the slot towards the cutting edge. The recess preferably has a configuration which parallels at least a portion of the cutting edge. Where the cutting edge is circular and the blade body has a planar surface between the fluid distribution guide surface and the cutting edge, for instance, the recess has a fluid distribution surface inclined with respect to the planar blade surface and extending along a circular arc.
In the manufacture of such a bone-cutting instrument, the blade body is generated separately and then affixed to the end of a tubular shaft. Thus there is a joint between the instrument shaft or horn and the blade.